Question 114797This question is from textbook
: Hi, I'm having trouble with this particular math problem and it would be very helpful if you can help me. The problem is: John and Mary leave their house at the same time and drive in opposite directions. John drives at 60 mi/h and travels 35 mi farther than Mary, who drives at 40 mi/h. Mary's tyip takes 15 min longer than John's. For what length of time does each of them drive?
This question is from textbook
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! John and Mary leave their house at the same time and drive in opposite directions. John drives at 60 mi/h and travels 35 mi farther than Mary, who drives at 40 mi/h. Mary's trip takes 15 min longer than John's. For what length of time does each of them drive?
:
Let t = John's driving time
then
(t+.25) = Mary's driving time (changed 15 min to .25 hr)
:
Write a distance equation Distance = speed * time:
:
J's distance - 35 = M's distance
60t - 35 = 40(t+.25)
:
60t - 35 = 40t + 10
:
60t - 40t = 10 + 35
:
20t = 45
:
t = 45/20
:
t = 2.25 hrs is John's driving time
and
2.25 + .25 = 2.5 hrs is Mary's driving time
:
:
Check solutions by finding the distance each drives:
J: 2.25 *60 = 135 mi
M: 2.50 *40 = 100 mi
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difference = 35 mi
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